Immediate pain alleviation in oral mucositis and other oral ulcerative diseases through photobiomodulation therapy: the preemptive treatment concept.

OBJECTIVE: Photobiomodulation (PBM) therapy is recommended by multiple international societies for managing oral mucositis (OM). These recommendations are based on extensive evidence. However, the search for an optimal PBM protocol continues. This mapping review focuses on a novel aspect of PBM therapy which is the immediate effect on pain levels associated with oral ulcerative conditions. DATA SOURCES: This literature review systematically compiles and evaluates the evidence about OM, alongside other oral ulcerative conditions, as the protocols that achieved pain relief for these oral conditions may have potential applicability to OM management. The scientific database used was PubMed. CONCLUSION: Whereas most of the randomized controlled trials about PBM therapy for OM and other ulcerative oral diseases reported delayed pain relief, certain PBM therapy protocols reported immediate pain relief. The results of this review highlight the concept of preemptive PBM therapy, in which PBM therapy is delivered early in the development of OM throughout the oncotherapy and may achieve immediate pain relief consistently in most of the patients and close to a negligible pain level. PBM therapy, as a powerful non-pharmacologic tool for immediate pain relief, has a great beneficial value in patients suffering from OM and other painful oral ulcerative diseases such as recurrent aphthous stomatitis and chronic graft-versus-host disease.

Morphological features of the photoplethysmographic signal: a new approach to characterize the microcirculatory response to photobiomodulation.

Introduction and Objectives: Advanced analysis of the morphological features of the photoplethysmographic (PPG) waveform may provide greater understanding of mechanisms of action of photobiomodulation (PBM). Photobiomodulation is a non-ionizing, red to near-infrared irradiation shown to induce peripheral vasodilatation, promote wound healing, and reduce pain. Using laser Doppler flowmetry combined with thermal imaging we found previously in a clinical study that PBM stimulates microcirculatory blood flow and that baseline palm skin temperature determines, at least in part, why some individuals respond favorably to PBM while others do not. "Responders" (n = 12) had a skin temperature range of 33°C-37.5°C, while "non-responders" (n = 8) had "cold" or "hot" skin temperature (<33°C or >37.5°C respectively). The continuous PPG signals recorded from the index fingers of both hands in the original clinical study were subjected to advanced post-acquisitional analysis in the current study, aiming to identify morphological features that may improve the accuracy of discrimination between potential responders and non-responders to PBM. Methods: The PPG signals were detrended by subtracting the lower envelope from the raw signal. The Root Mean Square (RMS) and Entropy features were extracted as were two additional morphological features -- Smoothness and number of local extrema per PPG beat (#Extrema). These describe the signal jaggedness and were developed specifically for this study. The Wilcoxon test was used for paired comparisons. Correlations were determined by the Spearman correlation test (rs). Results: The PPG waveforms of responders to PBM had increased amplitude and decreased jaggedness (Baseline vs. 10' post-irradiation: Entropy, 5.0 ± 1.3 vs. 3.9 ± 1.1, p = 0.012; #Extrema, 4.0 ± 1.1 vs. 3.0 ± 1.6, p = 0.009; RMS, 1.6 ± 0.9 vs. 2.3 ± 1.2, p = 0.004; Smoothness, 0.10 ± 0.05 vs. 0.19 ± 0.16, p = 0.016). In addition, unilateral irradiation resulted in a bilateral response, although the response of the contralateral, non-irradiated hand was shorter in duration and lower in magnitude. Although subjects with 'cold,' or 'hot,' baseline skin temperature appeared to have morphologically distinct PPG waveforms, representing vasoconstriction and vasodilatation, these were not affected by PBM irradiation. Conclusion: This pilot study indicates that post-acquisitional analysis of morphological features of the PPG waveform provides new measures for the exploration of microcirculation responsiveness to PBM.

Gamification of Cervical Spine Physiotherapy by Virtual Reality Software: Is This Real Rehabilitation?

Objective: Physical rehabilitation by virtual reality (VR) gamification is gaining acceptance. This study was designed to verify whether neck movements invoked by a fully immersive VR game environment may be physiotherapist-prescribed rehabilitation exercise. Methods: This was a single-visit prospective clinical trial (NCT03104647). Healthy participants put on VR headsets and entered a fully immersive game environment (VRPhysio, XRHealth, Tel Aviv, Israel) that prompted neck movement (flexion, extension, rotation, lateral bend, and combinations repeated twice in random order) accompanied by feedback encouraging correct performance. Four board-certified physiotherapists independently viewed videotapes recorded during the session, identified movements, and determined whether they were recommended as neck rehabilitation exercises. Results: Twenty (n = 20) participants (male-female ratio = 13:7; age = 38 ± 14 years old) completed the training session (16 movements per participant). All movements were identified correctly and determined to be appropriate for neck rehabilitation. No adverse events were reported. Conclusions: The VRPhysio software invoked movements identified by board-certified physiotherapists as appropriate for neck rehabilitation. The potential advantage of home-based VR gamification of cervical spine rehabilitation programs over common practice in motivating patient adherence warrants evaluation by randomized controlled trials.

Photobiomodulation self-treatment at home after rotator cuff arthroscopic repair accelerates improvement in pain, functionality, and quality of life: A double-blind, sham-controlled, randomized clinical trial.

OBJECTIVE: To determine whether self-applied photobiomodulation (PBM) therapy at home, following rotator cuff arthroscopic surgery (RCAS) can accelerate improvement in patient-reported outcomes within the first 6 months postsurgery. METHODS: This study was a prospective, double-blind, sham-controlled, randomized clinical trial (NCT04593342). Patients (n = 50, age 55 ± 7 years, male:female 29:21) who underwent primary RCAS were randomized to receive active (n = 22) or sham (n = 28) PBM devices (B-Cure Laser Pro, Erica B-Cure LASER Ltd., Haifa, Israel) in addition to standard care. Patients self-applied the treatments (808 nm, 15 min, 16.5 J/cm2 ) at home for 3 months postsurgery. Evaluations were conducted before the surgery (baseline) and at 1-3 and 6 months post-RCAS (FU-1M, FU-3M, FU-6M), and included Constant-Murley score (CMS), range of motion (ROM), subjective pain by visual analogue scale (VAS), disability by QuickDASH, and quality of life (QOL) by SF-12. The difference from baseline to follow-up (ΔFU), %patients achieving minimal clinical important difference (MCID), and patient acceptable symptom score (PASS) were calculated. Comparisons were conducted with superiority 2-sample t test and χ2 . RESULTS: Baseline values were not significantly different between groups. Both groups had similar improvements in CMS and ROM. However, compared to Sham, PBM significantly accelerated subjective pain reduction at 3 and 6 months (VAS mean ± SD, PBM-vs-Sham: ΔFU-3M 32 ± 33 vs. 16 ± 27, p = 0.040; ΔFU-6M: 41 ± 36 vs. 23 ± 26, p = 0.038), with a significantly higher proportion of patients achieving MCID at 3 months (76% vs. 48%, p = 0.027) and PASS at 6 months (48% vs. 23%, p = 0.044). PBM also significantly accelerated improvement in functionality and QOL at 6 months (QuickDASH ΔFU-6M: 30 ± 24 vs. 18 ± 14, p = 0.029; SF-12 physical component 6.8 ± 12.5 vs. 0.4 ± 8.6, p = 0.031; SF-12 mental component 8.5 ± 9.1 vs. 2.2 ± 12, p = 0.032). CONCLUSIONS: Self-applied photobiomodulation following RCAS significantly accelerates decrease in pain and disability, and improves QOL. This nonpharmacologic add-on therapeutic modality is easy to use and encourages active patient involvement. Its potential use in rehabilitation following other surgeries should be considered. LEVEL OF EVIDENCE: Level I, high-quality RCT.

High-power laser photobiomodulation therapy for immediate pain relief of refractory oral mucositis.

PURPOSE: We aimed to evaluate the efficacy of high-power (class IV) laser photobiomodulation (PBM) therapy for immediate pain relief due to oral mucositis (OM) refractory to recommended first-line therapy. METHODS: This retrospective study included 25 cancer patients with refractory chemotherapy- or radiotherapy-induced OM (16 and 9 patients, respectively) that were treated for pain relief with an intraoral InGaAsP diode laser (power density = 1.4 W/cm2 ). Pain was self-assessed immediately before and after laser treatment using a 0-to-10 numeric rating scale ([NRS], "0" = no pain, "10" = intolerable pain). RESULTS: Patients reported an immediate decrease in pain following 94% (74 of 79) of the PBM sessions, in 61% (48 sessions) the pain reduction was over 50%, and in 35% (28 sessions) the initial pain was completely eliminated. There were no reports of increased pain post-PBM. For chemotherapy and radiotherapy-treated patients, mean reduction in pain NRS post-PBM was 4.8 ± 2.5 (p < 0.001) and 4.5 ± 2.8 (p = 0.001), indicating a post-PBM reduction of 72% and 60% of the initial pain level, respectively. The analgesic benefit of PBM remained for a mean of 6.0 ± 5.1 days. One patient reported a transient burning sensation after one PBM session. CONCLUSIONS: High-power laser PBM may provide nonpharmacologic, patient-friendly, long-lasting, rapid pain relief for refractory OM.

Natural history of changes in knee skin temperature following total knee arthroplasty: a systematic review and meta-analysis.

Patients undergoing total-knee arthroplasty (TKA) have transient increases in anterior knee skin temperature (ST) that subside as recovery progresses-except in cases of systemic or local prosthetic joint infections (PJI). This meta-analysis was designed to quantify the changes in knee ST following TKA in patients with uncomplicated recovery as a prerequisite for assessing the usefulness of thermal imaging for diagnosis of PJI. This meta-analysis (PROSPERO-CRD42021269864) was performed according to PRISMA guidelines. PUBMED and EMBASE were searched for studies reporting knee ST of patients that underwent unilateral TKA with uncomplicated recovery. The primary outcome was the weighted means of the differences in ST between the operated and the non-operated knees (ΔST) for each time point (before TKA, and 1 day; 1,2, and 6 weeks; and 3,6, and 12-months post-TKA). For this analysis, 318 patients were included from 10 studies. The elevation in ST was greatest during the first 2-weeks (ΔST = 2.8 °C) and remained higher than pre-surgery levels at 4-6 weeks. At 3-months, ΔST was 1.4 °C. It decreased to 0.9 °C and 0.6 °C at 6 and 12-months respectively. Establishing the baseline profile of knee ST following TKA provides the necessary first step for evaluating the usefulness of thermography for the diagnosis of post-procedural PJI.

Pre-intubation ventilation device for bearded patients: prospective, randomized, crossover trial in anesthetized patients.

Having a beard is an independent predictor of difficult ventilation by face mask. This study evaluates the efficacy of a novel intra-oral Bag-Valve-Guedel Adaptor (BVGA) in anaesthetized bearded patients. Patients with ASA score 1-2, scheduled for elective surgery, were recruited for this prospective, crossover trial. Beard length was categorized as < 0.5 cm, 0.5-1 cm, 1-5 cm, or > 5 cm. Patients were ventilated by attending anesthesiologists using the BVGA and a facemask (both with a Guedel oral airway). End-tidal CO2 (EtCO2) and expiratory tidal volume (TV) were recorded as was the number of hands required for the procedure. The primary outcome was the difference between BVGA and Facemask. Sixty-one patients were enrolled. Of these, 38 had beards, and 23 were without beards or with beards < 0.5 cm length. In bearded patients, ventilation with the BVGA was superior to the face mask by EtCO2 and non-inferior by TV (BVGA-vs-Mask, mean [95% CI]: EtCO2 [mmHg], 33.0 [31.6, 34.3]-vs-27.2 [25.5, 28.8], p < 0.001; TV [ml∙kg-1 IBW], 8.1 [7.4, 8.9]-vs-6.9 [6.0, 7.7], p = 0.11). The BVGA was found to be superior to the face mask by EtCO2 across all beard lengths (p ≤ 0.001), but by TV only for the longest beard group (p = 0.009). After securing the BVGA, ventilation was possible without hands in 74% of the cases - clearly impossible with the facemask (p ≤ 0.001). The BVGA is more effective and more convenient than the facemask in anaesthetized bearded patients. A follow-up study is underway to test whether replacing the face mask with the BVGA will improve effectiveness and ease of pre-intubation field ventilation by less-experienced, first responders.

A real-world evaluation of an herbal treatment for infantile colic reported by 1218 parents in Israel.

PURPOSE: Infantile colic (IC) or fussing and crying behavior of unknown cause, affects up to 20% of the infant population and is one of the major reasons for parents to seek medical advice. Therapeutic options are limited and the key component for IC management is parental support. Fennel-based herbal treatments were shown to significantly reduce crying time. The current study was designed to evaluate the parent perception of effectiveness of a fennel-based commercially-available herbal treatment for IC (BabyCalm, Hisunit Ltd., Israel) using a retrospective online survey. DESIGN AND METHODS: This was a real-world observational, case-control retrospective study. Parents of babies with IC symptoms, who either used the herbal product for their baby or did not use any product were invited to participate in an online survey during August-December 2019. The primary outcome was the perceived level of treatment success and symptom improvement. RESULTS: 1218 parents of IC babies (48% females, 90% up to 3 months of age, 58% exclusively breast-fed) responded to the survey of whom 771 used the treatment. Significantly fewer IC-related symptoms were reported by parents who used the product compared to those that did not. Parents perceived the treatment as successful in 65% of the cases, reporting meaningful improvements within 30 min for 69%-79% of the symptoms. CONCLUSIONS: The majority of parents perceived the herbal treatment as effective in rapid symptom reduction suggesting that this may provide a satisfactory solution for IC in the community.

Intraosseous administration of freeze-dried plasma in the prehospital setting.

BACKGROUND: Freeze dried plasma (FDP) is a commonly used replacement fluid in the prehospital setting when blood products are unavailable. It is normally administered via a peripheral intravenous (PIV) line. However, in severe casualties, when establishing a PIV is difficult, administration via intraosseous vascular access is a practical alternative, particularly under field conditions. OBJECTIVES: To evaluate the indications and success rate of intraosseous administration of FDP in casualties treated by the Israel Defense Forces (IDF). METHODS: A retrospective analysis of data from the IDF-Trauma Registry was conducted. It included all casualties treated with FDP via intraosseous from 2013 to 2019 with additional data on the technical aspects of deployment collected from the caregivers of each case. RESULTS: Of 7223 casualties treated during the study period, intravascular access was attempted in 1744; intraosseous in 87 of those. FDP via intraosseous was attempted in 15 (0.86% of all casualties requiring intravascular access). The complication rate was 73% (11/15 of casualties). Complications were more frequent when the event included multiple casualties or when the injury included multiple organs. Of the 11 failed attempts, 5 were reported as due to slow flow of the FDP through the intraosseous apparatus. Complications in the remaining six were associated with deployment of the intraosseous device. CONCLUSIONS: Administration of FDP via intraosseous access in the field requires a high skill level.

Treatment of diabetic foot ulcers in a frail population with severe co-morbidities using at-home photobiomodulation laser therapy: a double-blind, randomized, sham-controlled pilot clinical study.

PURPOSE: To evaluate the safety and efficacy of an at-home photobiomodulation (PBM) device for the treatment of diabetic foot ulcers (DFUs) in a frail population with severe comorbidities. METHODS: Prospective, randomized, double-blind, sham-controlled pilot study. Patients (age = 63 ± 11 years, male:female 13:7) with insulin-dependent diabetes type 2, neuropathy, peripheral artery disease, significant co-morbidities, and large osteomyelitis-associated DFUs (University of Texas grade ≥ III) were randomized to receive active (n = 10) or sham (n = 10) at-home daily PBM treatments (pulsed near-infrared 808 nm Ga-Al-As laser, 250 mW, 8.8 J/cm2) for up to 12 weeks in addition to standard care. The primary outcome was the %wound size reduction. The secondary was adverse events. RESULTS: With the numbers available, PBM-treated group had significantly greater %reduction compared to sham (area [cm2], baseline vs endpoint: PBM 10[20.3] cm2 vs 0.2[2.4] cm2; sham, 7.9 [12.0] cm2 vs 4.6 [13.8] cm2, p = 0.018 by Mann-Whitney U test). Wound closure > 90% occurred in 7 of 10 PBM-treated patients but in only 1 of 10 sham patients (p = 0.006). No adverse device effects were observed. CONCLUSIONS: Photobiomodulation at home, in addition to standard care, may be effective for the treatment of severe DFUs in frail patients with co-morbidities and is particularly relevant at these times of social distancing. Our preliminary results justify the conduction of a larger clinical trial. CLINICALTRIALS: gov: NCT01493895.

A mathematical model of cardiovascular dynamics for the diagnosis and prognosis of hemorrhagic shock.

A variety of mathematical models of the cardiovascular system have been suggested over several years in order to describe the time-course of a series of physiological variables (i.e. heart rate, cardiac output, arterial pressure) relevant for the compensation mechanisms to perturbations, such as severe haemorrhage. The current study provides a simple but realistic mathematical description of cardiovascular dynamics that may be useful in the assessment and prognosis of hemorrhagic shock. The present work proposes a first version of a differential-algebraic equations model, the model dynamical ODE model for haemorrhage (dODEg). The model consists of 10 differential and 14 algebraic equations, incorporating 61 model parameters. This model is capable of replicating the changes in heart rate, mean arterial pressure and cardiac output after the onset of bleeding observed in four experimental animal preparations and fits well to the experimental data. By predicting the time-course of the physiological response after haemorrhage, the dODEg model presented here may be of significant value for the quantitative assessment of conventional or novel therapeutic regimens. The model may be applied to the prediction of survivability and to the determination of the urgency of evacuation towards definitive surgical treatment in the operational setting.

Photobiomodulation as an Adjunctive Treatment to Physiotherapy for Reduction of Anterior Knee Pain in Combat Soldiers: A Prospective, Double-Blind, Randomized, Pragmatic, Sham-Controlled Trial.

BACKGROUND AND OBJECTIVES: Anterior knee pain (AKP) is the most common knee pathology in athletes and occurs in 15% of army recruits of elite units during basic training. Of these, 50% are symptomatic 6 years later. Photobiomodulation (PBM) is a nonthermal red-to-near-infrared irradiation used for pain reduction of a variety of etiologies. This study was designed to determine whether addition of PBM to physiotherapy (PT) for AKP in combat soldiers is superior to PT alone. STUDY DESIGN/MATERIALS AND METHODS: In this prospective, double-blind, sham-controlled, randomized clinical trial (NCT02845869), 26 combat soldiers/policemen (male:female, 15:11; body mass index [BMI] = 24.2 ± 3.9, n = 46 knees), with AKP due to overuse/load, received 4 weeks of PT + sham (PT + Sham) or active PBM (wavelength = 660 and 850 nm, pulsing = 2.5 Hz, LED power = 50 mW/cm2 [local tissue/regional lymph nodes]; 810 nm continuous beam, laser cluster 6 W/cm2 [analgesia] and laser pointer 4.75 W/cm2 [trigger points]) (PT + PBM). The main outcome measures were subjective pain by visual analog scale (VAS) (0 [none]-100 [intolerable]) and functional disability by Kujala score (0 [worst]-100 [best]). Evaluations were carried out at baseline, end of treatments, and 3-month follow-up. RESULTS: All participants completed the treatment protocol without any reported adverse device effects. Post-treatment pain was significantly reduced in the PT+PBM group, compared with baseline and sham (Δpain, VAS, mean ± SD: PT + PBM = -19 ± 23, P = 0.002; PT + Sham = -6 ± 21, P = 0.16; between groups, P = 0.032). At 3-month follow-up, pain reduction was similar between groups; however, the Kujala score was significantly improved only in the PBM-treated group (ΔKujala: PT + PBM = 11 ± 10, P = 0.003; PT + Sham = 5 ± 7, P = 0.059). CONCLUSIONS: Addition of PBM to PT for AKP resulted in earlier reduction in pain and improved functionality, compared with PT alone. This noninvasive, nonpharmacologic, adjunctive therapeutic modality can be easily incorporated into team healthcare frameworks or end units and may lead to earlier return to competition or combat-level service. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

Remote ischemic preconditioning improves tissue oxygenation in a porcine model of controlled hemorrhage without fluid resuscitation.

Remote ischemic preconditioning (RIPC) involves deliberate, brief interruptions of blood flow to increase the tolerance of distant critical organs to ischemia. This study tests the effects of limb RIPC in a porcine model of controlled hemorrhage without replacement therapy simulating an extreme field situation of delayed evacuation to definitive care. Twenty-eight pigs (47 ± 6 kg) were assigned to: (1) control, no procedure (n = 7); (2) HS = hemorrhagic shock (n = 13); and (3) RIPC + HS = remote ischemic preconditioning followed by hemorrhage (n = 8). The animals were observed for 7 h after bleeding without fluid replacement. Survival rate between animals of the RIPC + HS group and those of the HS group were similar (HS, 6 of 13[46%]-vs-RIPC + HS, 4 of 8[50%], p = 0.86 by Chi-square). Animals of the RIPC + HS group had faster recovery of mean arterial pressure and developed higher heart rates without complications. They also had less decrease in pH and bicarbonate, and the increase in lactate began later. Global oxygen delivery was higher, and tissue oxygen extraction ratio lower, in RIPC + HS animals. These improvements after RIPC in hemodynamic and metabolic status provide essential substrates for improved cellular response after hemorrhage and reduction of the likelihood of potentially catastrophic consequences of the accompanying ischemia.

Supportive care of cancer patients with a self-applied photobiomodulation device: a case series.

PURPOSE: Oral mucositis (OM) and prolonged wound healing are common side-effects of cancer treatments. Photobiomodulation (PBM), previously called low-level laser, is currently part of the official guideline for OM prevention. However, all the PBM protocols relate to office-based devices, operated by professional health caregivers, requiring frequent applications. In the following case series, we present our experience with a self-applied consumer home-use PBM device for supportive care. METHODS: Five patients receiving cancer treatment presented at the clinic (female:male 3:2, 55-76 years old) with OM grade 3/4 (n=2), post-surgical non-healing wounds (n=3), and dermatitis (n=1). The PBM treatment (808 nm, 250 mW peak power, 15KHz, 5 J/min, ray size 4.5×1.0cm2) was self-applied by the patients. The protocol included extra/intra-oral applications, over the wound bed/margins and adjacent lymph nodes. RESULTS: The treatment was found effective for resolving OM with rapid pain relief and accelerated healing in post-operative wounds and dermatitis, without reported adverse events. Patients found routine easy to follow and painless, and the protocol was easily integrated as an adjuvant treatment to standard care at the clinic or home while not requiring additional time from the staff. CONCLUSIONS: Side-effects induced by cancer therapy have a detrimental effect on the patient's well-being and may delay or even prevent the patients from completing treatment regimens. PBM is already an established tool for supportive treatment in cancer patients. The advent of a self-applied personal PBM treatment with easy-to-apply protocols for a variety of side-effects makes this technology an important accessible and safe supportive care option.

Novel self-fixation chest drain device tested in a swine model of pneumo-hemothorax.

INTRODUCTION: Thoracic injuries account for 20-25% of trauma-related deaths. In cases of pneumothorax the insertion of a chest tube is mandatory but associated with high complication rates particularly when inserted under difficult conditions. The C-Lant is a novel chest-tube insertion device that provides integrated double fixation capabilities and can be used by responders with minimal experience. The aim of the study was to test the device in a large animal model. MATERIAL AND METHODS: Pneumothorax, tension pneumothorax, and hemothorax were induced in four white domestic female pigs. The C-Lant device (Vigor Medical Technologies, Haifa, Israel) was inserted as any chest-drain to decompress the thorax. Pull test was applied to test the strength of device fixation. RESULTS: The insertion of the device was simple and effective without detectable negative physiological effects. Reliable fixation was achieved without difficulty. Air and liquid were promptly drained from the chest cavity. Minimal tissue laceration occurred when applying the device in a scenario of erroneous pneumothorax diagnosis with fully expanded lungs. Interconnection with other surgical accessories was smooth. CONCLUSION: The C-Lant is a novel device that facilitates easy insertion and fixation of chest-tubes by minimally experienced medical providers and reduces the likelihood of unwanted expulsion. Clinical studies are planned.

Photobiomodulation and estrogen stabilize mitochondrial membrane potential in angiotensin-II challenged porcine aortic smooth muscle cells.

Rupture of Abdominal aortic aneurysm (AAA) is among the 15 leading causes of death after age 65. Using high frequency ultrasound, we showed that photobiomodulation (PBM) prevents formation and progression of AAA in the angiotensin-II (Ang-II)-infused, apolipoprotein-e-deficient mouse model. In the current study we report that while challenge of porcine aortic Smooth Muscle Cells (SMCs) with Ang-II (1 µM) resulted in a marked decay in mitochondrial membrane potential (MitMP) vs non-challenged cells, treatment with PBM (continuous diode laser, 780 nm, 6.7 mW/cm2 , 5 minutes, 2 J/cm2 ) or pre-incubation with estrogen (50 nM, 1 hour) significantly attenuated this deterioration in MitMP. We also report that PBM and estrogen markedly affected porcine aortic SMC contraction and modified mitochondrial dispersion reflecting important influence on SMC function. These studies provide strong evidence of the important underlying role of mitochondria in the preventive effect of PBM on formation and progression of AAA and its reduced incidence and delayed onset in women.